The goals of this Mentored Patient-Oriented Research Career Development Award (K23) are to allow the applicant (1) to acquire the knowledge base necessary to conduct research analyzing patterns of non-response following an initial antidepressant intervention in primary care settings, and (2) to use this information to accurately target those nonresponding patients appropriately seen in primary care settings for adjunctive psychosocial interventions. The five-year award will allow the applicant to refine his research skills in clinical epidemiology and health services research and to apply them toward the conduct of clinical effectiveness trials. The aim of this line of research is to decrease the persistence, recurrence and disability of depressive illness in primary care settings. The career development plan proposes coursework, practical and mentored research activities to support learning in three core areas: clinical epidemiology, biostatistics, and health services research; cognitive-behavioral treatment (CBT) in primary care settings; and clinical effectiveness trials design in primary care settings. Project 1 will be a secondary data analysis of a prospective, longitudinal public sector primary care data set to 1) identify pre-treatment characteristics which can predict categories of response following an adequate antidepressant trial, and 2) identify the time point after treatment initiation when those patients who have yet to fully respond are unlikely to do so after an adequate trial. Such an analysis will allow us to better understand the various patterns of response to an initial antidepressant intervention, and it will help us to better understand the causes of non-response by identifying key related pre-treatment characteristics. Based on results of the above analysis, Project 2 will test the feasibility of conducting a multi-site randomized clinical trial in primary care that assesses the effectiveness of a targeted adjunctive CBT intervention, and it will test the feasibility of applying pre-treatment measures identified in Project 1 to predict levels of response to standard medication management. This project will provide preliminary data and guide the design of a subsequent multi-site R-01 application, whose submission will occur in year 3. The five year K23 award will enable the applicant to obtain the research skills required to become an independent investigator able to translate both the clinical epidemiologic and quality of care strengths of practice research and the population-based strengths of effectiveness research into clinically relevant interventions research. The applicant's career will be devoted to developing a program of research focused on helping primary care clinicians target treatment resistant depressed patients for the provision of cost-effective adjunctive psychosocial interventions.